Shared flat and subletting: when can I sublet? (2026)
Shared flat and subletting: when can I sublet?
On the contract model, one joint tenancy, individual contracts, or a head tenant with subtenants.
That is what decides who is liable to the landlord. For part of the flat you have a right to permission to sublet (§ 553 Abs. 1 BGB); the whole flat you may let only with express consent (§ 540 BGB).
§ 421 BGBIn 60 seconds
Under one joint tenancy all flatmates are head tenants and are jointly and severally liable: any one of them can be pursued for the whole rent (§ 421 BGB).
With individual contracts per room, each person is liable only for their own rent; no joint and several liability arises.
Under the head-tenant-plus-subtenants model only the head tenant is liable to the landlord, and needs permission under § 553 BGB for every sublet.
Under a joint tenancy an insolvent flatmate can cost you the whole rent; settle the model before you move in.
Subletting for profit or on a short-term basis regularly founds no legitimate interest under the case law: the right supports sharing costs, not running a business.
What the law says
Where several people owe performance such that each is obliged to render the whole, but the creditor is entitled to it only once, the creditor may demand performance from any one of them in whole or in part, at their discretion. Under a joint flatshare tenancy that means: the landlord may pursue a single person. Working translation; the German original is the binding text.
Three flatshare models compared
| Model | Who is the contracting party | Liability to the landlord |
|---|---|---|
| One joint tenancy | all flatmates as head tenants | joint and several, each for the whole rent (§ 421 BGB) |
| Individual contracts per room | each person separately with the landlord | only for their own rent, no joint and several liability |
| Head tenant plus subtenants | the head tenant only (subtenants via § 553 BGB) | the head tenant alone is liable |
How to obtain permission in practice, naming the person, stating the rooms, setting out the legitimate interest, is in Taking in a subtenant. How to split rent and Nebenkosten between yourselves is in Splitting Nebenkosten in a flatshare.
What it means for each side
- Settle the contract model before you move in: your exposure follows from it.
- Under a joint tenancy, expect that you may have to cover for others.
- As head tenant, get permission for every sublet.
- Record in writing between yourselves who pays what share.
- Set the model out unambiguously in the contract.
- Under a joint tenancy you may pursue a single person.
- For part-subletting with a legitimate interest there is a right.
- Over the whole flat you decide freely (§ 540 BGB).
Common mistakes
Under a joint tenancy an insolvent flatmate can cost you the whole rent.
The right under § 553 BGB does not substitute for the permission itself. A warning and termination can follow.
The right covers part only; the whole needs consent under § 540 BGB.
Profit-driven or short-term subletting regularly founds no legitimate interest.
What to do next
Check the contract model: one joint tenancy, individual contracts, or the head-tenant model?
Under a joint tenancy, settle the joint and several exposure between yourselves.
For every room sublet, get permission in writing, with the name and start date.
When a flatmate changes, adjust the contract properly rather than swapping quietly.
Frequently asked questions
Can I sublet without the landlord's permission?
No. Any handover of use to a third party needs the landlord's permission (§ 540 BGB). For part of the dwelling, however, § 553 Abs. 1 BGB gives you a claim to that permission, provided a berechtigtes Interesse (legitimate interest) arises after the contract is signed. Subletting without permission risks an Abmahnung (formal warning) and Kündigung (termination).
What counts as a berechtigtes Interesse under § 553 BGB?
A berechtigtes Interesse (legitimate interest) is any reasonable ground that arose after the contract was signed, for example wanting to lower your rent burden by taking in a subtenant, a partner or WG flatmate moving in, or a longer work- or study-related stay elsewhere while you keep the flat. Economic or personal reasons of some weight are enough.
Can the landlord charge an Untermietzuschlag?
Yes, if the handover is only reasonable for the landlord with an appropriate rent increase (§ 553 Abs. 2 BGB). In practice, an Untermietzuschlag (subletting surcharge) of roughly 10 to 20 percent of the sublet rent is regarded as appropriate. A flat surcharge with no factual basis is not permitted.
Can the landlord refuse permission?
Only for good cause: where there is an important reason in the person of the third party, where the dwelling would be overcrowded, or where the handover is otherwise unreasonable for the landlord (§ 553 Abs. 1 Satz 2 BGB). If permission is refused without justification, you may terminate the tenancy extraordinarily with the notice period set by law (§ 540 Abs. 1 Satz 2 BGB).
Who is liable for the rent in a WG (shared flat)?
It depends on the contract. Under a single joint contract, all main tenants are liable as Gesamtschuldner (joint and several debtors). The landlord can demand the full rent from any one of them. Under separate per-room contracts, each person is liable only for their own rent. Under the main-tenant-plus-subtenants model, only the main tenant is liable to the landlord.
Can I sublet my whole flat, for example via Airbnb?
Handing over the entire dwelling needs the landlord's express consent (§ 540 BGB) and is not covered by the claim under § 553 BGB, which applies only to part. Profit-oriented short-term subletting (for example via platforms) generally does not establish a berechtigtes Interesse under German Federal Court of Justice (BGH) case law.
This page gives general information as at the date shown. It does not replace legal advice on an individual case.